- cattle plague
- costiasis
- chorea
- Chartism
- curlew
- carhop
- corvette
- companionship
- cosmic ray
- carbamide
- cuisine
- courtyard
- compound eye
- code of conduct
- crossbow
- cosmic
- conduction
- chlorosis
- crusher
- corer
- chromatic
- colour blindness
- chromaticity
- corollary
- complicated
- cosmolatry
- cold sweat
- cartel
- critical point
- canted
- collar cell
- crestfallen
- chipping
- cordon
- consensus
- concordance
- chemical action
- chemical process
- catarrh
- criminal court
- chlorine dioxide
- crossfire
- commonality
- caucus
- college
- chaotic
- collective
- coding
- cryptogram
- capitulum